The runners, including groups that had arrived from abroad and members of Achilles International, who support marathoners with disabilities, started arriving just after dawn to run laps around the park, clocking the distance on their Garmin watches.

There were none of the usual crowds or water stations, but small groups of spectators dotted the makeshift route and cheered on the runners. And a few individuals handed out water cups and collected garbage.

Things were most lively by the finish line, which was fenced off but swarming with runners and their families.